Are you looking for a way to increase the speed of an Express Video in USMLE-Rx? Or even slow it down? You can adjust the speed for each video in the video player's controls at the bottom of the screen.
You can change the speed from 1x (which is normal speed) to:
This quick video shows how to do it.
Please note that this feature isn't available in the mobile app yet, though it will be in the near future.